From 3b3b1e3202eb1c375c842a8cb629668047882fb8 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 5 Jan 2002 23:38:28 -0800 Subject: [PATCH] cfgcleanup.c (try_forward_edges): Detect infinite loops while jump threading. * cfgcleanup.c (try_forward_edges): Detect infinite loops while jump threading. From-SVN: r48574 --- gcc/ChangeLog | 5 +++++ gcc/cfgcleanup.c | 30 +++++++++++++++++++++++++++--- 2 files changed, 32 insertions(+), 3 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7a4adfcf54c..292a19533c1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2002-01-05 Richard Henderson + + * cfgcleanup.c (try_forward_edges): Detect infinite loops while + jump threading. + 2002-01-05 Richard Henderson * c-decl.c (c_expand_body): Don't call outlining_inline_function. diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c index 96dee62519e..69045a08f3b 100644 --- a/gcc/cfgcleanup.c +++ b/gcc/cfgcleanup.c @@ -412,12 +412,32 @@ try_forward_edges (mode, b) edge t = thread_jump (mode, e, target); if (t) { - new_target = t->dest; - new_target_threaded = true; if (!nthreaded_edges) threaded_edges = xmalloc (sizeof (*threaded_edges) * n_basic_blocks); + else + { + int i; + + /* Detect an infinite loop across blocks not + including the start block. */ + for (i = 0; i < nthreaded_edges; ++i) + if (threaded_edges[i] == t) + break; + if (i < nthreaded_edges) + break; + } + + /* Detect an infinite loop across the start block. */ + if (t->dest == b) + break; + + if (nthreaded_edges >= n_basic_blocks) + abort (); threaded_edges[nthreaded_edges++] = t; + + new_target = t->dest; + new_target_threaded = true; } } @@ -504,7 +524,11 @@ try_forward_edges (mode, b) first->succ->count -= edge_count; first->frequency -= edge_frequency; if (first->succ->succ_next) - t = threaded_edges [n++]; + { + if (n >= nthreaded_edges) + abort (); + t = threaded_edges [n++]; + } else t = first->succ; -- 2.30.2